you can do 245/35 fronts (same as stock)
but the rear is prob gonna be a 10.5 width rim, so at the least I would do 285/30 (stock is 265/35)
believe it or not but in going with the 30 series tire the size that matches oem diameter the closest is the 305/30.

I am afraid that they are not able to do the 9.5 front, right now.
The monoblocks come with 9" and 10.5" forgings. for the M3.
the other sizes that they have are the 8.5 +30 and 10.0 +36, which are for the Non-M cars.